Fluid couplings are configured to provide fluid communication between two fluid passages. Some fluid coupling configurations include a nut and a body. Such fluid coupling configurations are often used in automotive brake line applications, and include those defined by SAE J533 and JASO F402 standards. The body defines a threaded bore. At the terminal end of the bore, a first fluid passage terminates at a protuberant seat. The nut includes threads that are engageable with the threads of the bore so that rotation of the nut inside the bore causes axial movement of the nut. The nut also defines a hole that extends therethrough.
A tube defines a second fluid passage and extends through the hole of the nut. The tube is positioned with respect to the nut such that, as torque is applied to the nut, the nut applies an axial load to the tube, which urges the end of the tube into contact with the seat, thereby establishing fluid communication between the first and second fluid passageways. The nut also transfers some of the torque to the tube.